Imageable seamed belts having polyamide adhesive between interlocking seaming members

ABSTRACT

A seamed flexible belt having a substrate and a seam having interlocking seam members, wherein the interlocking seam members are held together by an adhesive having polyamide and an optional electrically conductive filler, for use in electrostatographic, contact electrostatic, digital and other like printing machines.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] Attention is directed to U.S. patent application Ser. No.09/493,445 (D/97525D), filed Jan. 28, 2000, entitled “Process andApparatus for Producing an Endless Seamed Belt;” U.S. patent applicationSer. No. 09/470,931 (D/99689) filed Dec. 22, 1999, entitled, “ContinuousProcess for Manufacturing Imageable Seamed Belts for Printers;” U.S.patent application Ser. No. 09/088,011, (D/97683), filed May 28, 1998,entitled, “Unsaturated Carbonate Adhesives for Component Seams;” U.S.patent application Ser. No. 09/615,444 (D/99598), filed Jul. 13, 2000,entitled, “Polyimide Adhesive For Polyimide Component InterlockingSeams;” U.S. patent application Ser. No. 09/615,426 (D/99598Q), filedJul. 13, 2000, entitled. “Process For Seaming Interlocking Seams OfPolyimide Component Using Polyimide Adhesive”; U.S. patent applicationSer. No. 09/660,248 (D/99610), filed Sep. 13, 2000, entitled, “ImageableSeamed Belts Having Fluoropolymer Adhesive Between Interlocking SeamingMembers;” U.S. patent application Ser. No. 09/660,249 (D/99610Q), filedSep. 13, 2000, entitled, “Imageable Seamed Belts Having FluoropolymerOvercoat;” U.S. patent application Ser. No. ______ (A0895) filed ______,entitled, “Imageable Seamed Belts Having Hot Melt Processable,Thermosetting Resin and Conductive Carbon Filler Adhesive BetweenInterlocking Seaming Members;” U.S. patent application Ser. No. ______(D/A0895Q), filed ______, entitled, “Conductive Carbon Filled PolyvinylButyral Adhesive;” U.S. patent application Ser. No. ______ (D/A0895Q1),filed ______, entitled, “Dual Curing Process for Producing a Puzzle CutSeam;” and U.S. patent application Ser. No. ______ (A0584Q) filed______, entitled “Polyamide and Conductive Filler Adhesive.” Thedisclosures of each of these references are hereby incorporated byreference in their entirety.

BACKGROUND OF THE INVENTION

[0002] The present invention is directed to transfer members useful inelectrostatographic, including digital printing apparatuses. In specificembodiments, the present invention is directed to seamed belts, and morespecifically, to endless flexible seamed belts wherein an image can betransferred at the seam of the belt with little or no print defectscaused by the seam. In embodiments, the present invention relates toxerographic component Imageable seamed belts comprising an adhesiveformed between mutually mating elements of a seam, wherein the adhesivecomprises a polymer, optionally with electrically conductive fillerdispersed or contained therein. In a particularly preferred embodiment,the polymer is a polyamide. Preferably, the filler, if present, is anelectrically conductive filler such as a carbon filler, a metal oxidefiller, a polymer filler, a charge-transporting molecule, or a mixturethereof. The present invention further provides, in embodiments, a belthaving a seam with increased strength because the adhesive iscrosslinked. However, the belt is still flexible enough to withstand180° crease without cracking. The present invention, in embodiments,also provides a belt having a seam in which the height differentialbetween the seam and the rest of the belt is virtually nil. The belt, inembodiments, allows for image transfer at the seam, which cannot beaccomplished with known seamed belts. Image transfer is accomplishedpartly because the present seam possesses the desired conductivity andrelease properties required for sufficient transfer. The presentinvention also provides, in embodiments, a ripple-free seam. Further, inembodiments, the seam can be rapidly cured at relatively lowtemperatures. In addition, the seam, in embodiments, is resistant toalcohol and organic solvents. Moreover, in embodiments, there is notenting in the seam area. The seam, in embodiments, can withstandrepeated electrical transfer cycles and remain functional. Inembodiments, the adhesive withstands temperature transients between 25and 130° C., and is resistant to ambient changes in relative humidity.The seam is virtually to totally invisible to the xerographic imagingprocess.

[0003] In a typical electrostatographic reproducing apparatus such as anelectrophotographic imaging system using a photosensitive member, alight image of an original to be copied is recorded in the form of anelectrostatic latent image upon a photosensitive member and the latentimage is subsequently rendered visible by the application of a developermixture. One type of developer used in such printing machines is aliquid developer comprising a liquid carrier having toner particlesdispersed therein. Generally, the toner is made up of resin and asuitable colorant such as a dye or pigment. Conventional charge directorcompounds may also be present. The liquid developer material is broughtinto contact with the electrostatic latent image and the colored tonerparticles are deposited thereon in image configuration.

[0004] In a more typical electrostatic reproducing apparatus, thedeveloper consists of polymeric coated magnetic carrier beads andthermoplastic toner particles of opposite triboelectric polarity withrespect to the carrier beads. This is the dry xerographic process.

[0005] The developed toner image recorded on the imaging member istransferred to an image receiving substrate such as paper via a transfermember. The toner particles may be transferred by heat and/or pressureto a transfer member, or more commonly, the toner imrage particles maybe electrostatically transferred to the transfer member by means of anelectrical potential between the imaging member and the transfer member.After the toner has been transferred to the transfer member, it is thentransferred to the image receiving substrate, for example by contactingthe substrate with the toner image on the transfer memberelectrostatically or under heat and/or pressure.

[0006] Transfer members enable high throughput at modest process speeds.In four-color photocopier or printer systems, the transfer member alsoimproves registration of the final color toner image. In such systems,the four component colors of cyan, yellow, magenta and black may besynchronously developed onto one or more imaging members and transferredin registration onto a transfer member at a transfer station.

[0007] In electrostatographic printing and photocopy machines in whichthe toner image is transferred from the transfer member to the imagereceiving substrate, it is desired that the transfer of the tonerparticles from the transfer member to the image receiving substrate besubstantially 100 percent. Less than complete transfer to the imagereceiving substrate results in image degradation and low resolution.Complete transfer is particularly desirable when the imaging processinvolves generating full color images since undesirable colordeterioration in the final colors can occur when the color images arenot completely transferred from the transfer member.

[0008] Thus, it is desirable that the transfer member surface hasexcellent release characteristics with respect to the toner particles.Conventional materials known in the art for use as transfer membersoften possess the strength, conformability and electrical conductivitynecessary for use as transfer members, but can suffer from poor tonerrelease characteristics, especially with respect to higher gloss imagereceiving substrates.

[0009] Polyimide substrate transfer imaging members are suitable forhigh performance applications because of their outstanding mechanicalstrength and thermal stability, in addition to their good resistance toa wide range of chemicals. However, the high cost of manufacturingunseamed polyimide belts has led to the introduction of a seamed belt.Even polyimides with the best mechanical and chemical properties oftenexhibit poor adhesion at the seam even when commercially availableprimers and adhesives are used.

[0010] In the electrostatic transfer applications, use of a seamedtransfer polyimide member results in insufficient transfer in that thedeveloped image occurring on the seam is not adequately transferred.This incomplete transfer is partially the result of the difference inseam height to the rest of the belt. A “bump” is formed at the seam,thereby hindering transfer and mechanical performance. The developmentof puzzle cut seams has increased the quality of transfer somewhat, bydecreasing the seam height, thereby allowing smooth cycling. However,even with the improvements made with puzzle cut seams, quality imagingin the seamed area has not been obtainable at present due, in part, tocontrast in transfer caused by differences in electrical and releaseproperties of known seaming adhesives. Further, current adhesives do notprovide sufficient bonding strength at the seam, resulting in short beltlife. In addition, the seam must have the appropriate surface propertiesin order to allow for sufficient toner release at the seam.

[0011] Currently, puzzle cut and overlap seam adhesives consist ofuv-curable epoxies and hot-melt adhesives. While these adhesives exhibitacceptable strengths at room temperature under tensile load, mostundergo premature failure at elevated temperatures. Additionally, theexisting adhesives have been found to perform poorly under someimportant dynamic test conditions. Because the adhesive seam is notImageable, most machines do not develop images on the seam area, ornon-seamed belts are used.

[0012] Improved seam adhesives such as polyamic acid adhesives, haveproven to be strong. However, adhesives such as polyamic acid adhesivesrequire long cure times at elevated temperatures (for example, 1 hour at200° C.) with loss of water as the polyimide seam is formed. Theresulting differential shrinkage causes ripples as the adhesive curesand the cured seams are not completely filled with adhesive. If one sideof the puzzle cut seam is glued, tenting occurs. If both sides of thepuzzle cut seam are treated with polyamic acid adhesive, ripples form.Such ripples in the seam cause uneven development and ultimately resultin print defects, and a reduced belt life. Thus, adhesive alternativesto polyamic acid must be considered.

[0013] Therefore, it is desired to provide an adhesive system useful toseam puzzle cut seamed belts, wherein the height differential betweenthe seam and the rest of the belt is virtually nil, and the occurrenceof ripples and tenting in the seam is reduced or eliminated. It isfurther desirable to provide an adhesive that has a low temperaturerapid cure in order to increase production of the belts at a reducedproduction cost. It is also desirable to provide an adhesive that isresistant to alcohol and organic solvents. Further, it is desired toprovide an adhesive having electrical, mechanical and toner releasecharacteristics that closely match those of the substrates. Also, it isdesirable to provide an adhesive which is able to withstand transientsin temperatures between 25 and 130° C., and which is resistant tohumidity changes. In addition, it is desirable to provide a seam, whichis Imageable; thereby reducing or eliminating the presence of print orcopy defects. It is desirable to have a low temperature-curing adhesiveto eliminate ripple and substrate defects due to differential shrinkageof the belt and adhesive. Moreover, it is desirable to provide anadhesive, which allows for a belt flexible enough to withstand 180° bendor crease without cracking, yet strong enough to withstand multiplecycling.

[0014] U.S. Pat. No. 5,549,193 relates to an endless flexible seamedbelt comprising puzzle cut members, wherein at least one receptacle hasa substantial depth in a portion of the belt material at the belt ends.

[0015] U.S. Pat. No. 5,721,032 discloses a puzzle cut seamed belt havinga strength-enhancing strip.

[0016] U.S. Pat. No. 5,487,707 discloses a puzzle cut seamed belt havinga bond between adjacent surfaces, wherein an ultraviolet cured adhesiveis used to bond the adjacent surfaces.

[0017] U.S. Pat. No. 5,514,436 relates to a puzzle cut seamed belthaving a mechanically invisible seam, which is substantially equivalentin performance to a seamless belt.

SUMMARY OF THE INVENTION

[0018] Embodiments of the present invention include: an endless seamedflexible belt comprising a first end and a second end, each of the firstend and the second end comprising a plurality of mutually matingelements which join in an interlocking relationship to form a seam, thebelt comprising a substrate and the seam comprising an adhesivecomprising a polyamide.

[0019] In addition, embodiments of the present invention include: anendless seamed flexible belt comprising a first end and a second end,each of the first end and the second end comprising a plurality ofmutually mating elements which join in an interlocking relationship toform a seam, said belt comprising a polyimide substrate, and the seamcomprising an adhesive comprising an alcohol-soluble polyamide and anelectrically conductive filler.

[0020] Embodiments further include: an image forming apparatus forforming images on a recording medium comprising: a charge-retentivesurface to receive an electrostatic latent image thereon; a developmentcomponent to apply toner to the charge-retentive surface to develop theelectrostatic latent image to form a developed image on said chargeretentive surface; a transfer belt to transfer the developed image fromthe charge retentive surface to a copy substrate, wherein the transferbelt is an endless seamed flexible belt comprising a first end and asecond end, each of the first end and the second end comprising aplurality of mutually mating elements which join in an interlockingrelationship to form a seam, the transfer belt comprising a substrateand the seam comprising an adhesive comprising a polyamide; and a fixingcomponent to fuse the developed image to the copy substrate.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a better understanding of the present invention, referencemay be had to the accompanying figures.

[0022]FIG. 1 is a depiction of an electrostatographic apparatus.

[0023]FIG. 2 is an enlargement of a transfer system according to anembodiment of the present invention.

[0024]FIG. 3 is an enhanced view of an embodiment of a beltconfiguration and seam according to the present invention.

[0025]FIG. 4 is an enlargement of a puzzle cut seam having amultiplicity of head and neck members according to one embodiment of thepresent invention.

[0026]FIG. 5 is an enlargement of a puzzle cut seam havingmushroom-shaped puzzle cut members according to another embodiment ofthe present invention.

[0027]FIG. 6 is an enlargement of a puzzle cut seam having dovetailmembers according to another embodiment of the present invention.

[0028]FIG. 7 is an enlargement of a puzzle cut seam having receptacles(recessors) and teeth members according to another embodiment of thepresent invention.

[0029]FIG. 8 is an enlargement of a puzzle cut seam having receptacleand projection members of differing depth according to anotherembodiment of the present invention.

[0030]FIG. 9 is an enlarged version of a belt according to oneembodiment of the present invention and demonstrates a crevice betweenthe puzzle cut members, the crevice containing an adhesive.

[0031]FIG. 10 is an enlarged cross-sectional view of a belt according toa preferred embodiment of the invention.

[0032]FIG. 11 is a graph of conductivities (S/cm) as a function ofapplied field (V/cm) for samples of polyamide adhesives, which do notinclude a filler.

[0033]FIG. 12 is a graph of conductivities (S/cm) as a function ofapplied field (V/cm) for samples of polyamide adhesives after variousamounts, of carbon black have been added.

[0034]FIG. 13 is a graph of conductivities of these samples as afunction of the carbon black loading at different field strengths.

DETAILED DESCRIPTION OF THE PRESENT INVENTION

[0035] The present invention relates to an endless flexible seamed belthaving a puzzle cut seam, wherein the seam comprises an adhesivecomprising a polymer and optionally, an electrically conductive filler.In preferred embodiments, the polymer is a polyamide material. Theinvention provides, in embodiments, an adhesive system useful to seampuzzle cut seamed belts, wherein the height differential between theseam and the rest of the belt is virtually nil, and wherein theoccurrence of ripples and tenting in the seam is reduced or eliminated.The present invention further provides, in embodiments, an adhesive thathas a low temperature rapid cure in order to increase production of thebelts at a reduced production cost. Further, the present inventionprovides, in embodiments, an adhesive that is resistant to alcohol andorganic solvents. The adhesive system, in embodiments, also allows theseam to have thermal and mechanical characteristics closely matchingthose of the robust substrate. The present invention, in embodimentsallows for a belt flexible enough to withstand 180° bend or creasewithout cracking, yet strong enough to withstand multiple cycling. Theadhesive has electrical and mechanical properties which, in embodiments,can withstand transients in temperatures between 25 and 130° C., and isresistant to changes in humidity. In addition, the invention, inembodiments, provides an adhesive having electrical, mechanical andtoner release characteristics that closely match those of thesubstrates. Moreover, the invention, in embodiments, provides a seam,which is Imageable, thereby reducing or eliminating the presence ofprint or copy defects. Moreover, the seam, in embodiments, allows forextended life of the belt.

[0036] In preferred embodiments, the belt is an intermediate transferbelt, sheet, roller, or film useful in xerographic, including digital,apparatuses. However, the belts herein having a seam comprising apolyamide and optional filler can be useful as belts, rollers, drelts (ahybrid of a drum and a belt), and the like, for many different processesand components such as, photoreceplors, fusing members, transfixmembers, bias transfer members, bias charging members, developermembers, image bearing members, conveyor members, cleaning members, andother members for contact electrostatic printing applications,xerographic applications, including digital, and the like. Further, thebelts, herein, can be used for both liquid and dry powder xerographicarchitectures, although dry is preferred.

[0037] Referring to FIG. 1, in a typical electrostatographic reproducingapparatus, a light image of an original to be copied is recorded in theform of an electrostatic latent image upon a photosensitive member andthe latent image is subsequently rendered visible by the application ofelectroscopic thermoplastic resin particles which are commonly referredto as toner, specifically, photoreceptor 10 is charged on its surface bymeans of: an electrical charger 12 to which a voltage has been suppliedfrom power supply 11. The photoreceptor is then imagewise exposed tolight from an optical system or an image input apparatus 13, such as alaser and light emitting diode, to form an electrostatic latent imagethereon. Generally, the electrostatic latent image is developed bybringing a developer mixture from developer station 14 into contacttherewith. Development can be effected by use of a magnetic brush,powder cloud, or other known development process.

[0038] After the toner particles have been deposited on thephotoconductive surface, in image configuration, they are transferred toa copy sheet 16 by transfer means 15, which can be pressure transfer orelectrostatic transfer. Preferably, the developed image can betransferred to an intermediate transfer member and subsequentlytransferred to a copy sheet.

[0039] After the transfer of the developed image is completed, copysheet 16 advances to fusing station 19, depicted in FIG. 1 as fusing andpressure rolls, wherein the developed image is fused to copy sheet 16 bypassing copy sheet 16 between the fusing member 20 and pressure member21, thereby forming a permanent image. Fusing may be accomplished byother fusing members such as a fusing belt in pressure contact with apressure roller, fusing roller in contact with a pressure belt, or otherlike systems. Photoreceptor 10, subsequent to transfer, advances tocleaning station 17, wherein any toner left on photoreceptor 10 iscleaned therefrom by use of a blade 22 (as shown in FIG. 1), brush, orother cleaning apparatus.

[0040]FIG. 2 is a schematic view of an image development systemcontaining an intermediate transfer member. FIG. 2 demonstrates anotherembodiment of the present invention and depicts a transfer apparatus 15comprising a transfer member 1 positioned between an imaging member 10and a transfer roller 6. The imaging member 10 is exemplified by aphotoreceptor drum. However, other appropriate imaging members mayinclude other electrostatographic imaging receptors such as ionographicbelts and drums, electrophotographic belts, and the like.

[0041] In the multi-imaging system of FIG. 2, each image beingtransferred is formed on the imaging drum by image forming station 12.Each of these images is then developed at developing station 13 andtransferred to transfer member 2. Each of the images may be formed onthe photoreceptor drum 10 and developed sequentially and thentransferred to the transfer member 2. In an alternative method, eachimage may be formed on the photoreceptor drum 10, developed, andtransferred in registration to the transfer member 2. In a preferredembodiment of the invention, the multi-image system is, a color copyingsystem. In this color copying system, each color of an image beingcopied is formed on the photoreceptor drum. Each color image isdeveloped and transferred to the transfer member 2. As above, each ofthe colored images may be formed on the drum 10 and developedsequentially and then transferred to the transfer member 2. In thealternative method, each color of an image may be formed on thephotoreceptor drum 10, developed, and transferred in registration to thetransfer member 2.

[0042] After latent image forming station 12 has formed the latent imageon the photoreceptor drum 10 and the latent image of the photoreceptorhave been developed at developing station 13, the charged tonerparticles 4 from the developing station 13 are attracted and held by thephotoreceptor drum 10 because the photoreceptor drum 10 possesses acharge 5 opposite to that of the toner particles 4. In FIG. 2, the tonerparticles are shown as negatively charged and the photoreceptor drum 10is shown as positively charged. These charges can be reversed, dependingon the nature of the toner and the machinery being used. In a preferredembodiment, the toner is present in a liquid developer. However, thepresent invention, in embodiments, is useful for dry development systemsalso.

[0043] A biased transfer roller 6 positioned opposite the photoreceptordrum 10 has a higher voltage than the surface of the photoreceptor drum10. As shown in FIG. 2, biased transfer roller 6 charges the backside 7of transfer member 2 with a positive charge. In an alternativeembodiment of the invention, a corona or any other charging mechanismmay be used to charge the backside 7 of the transfer member 2.

[0044] The negatively charged toner particles 4 are attracted to thefront side 8 of the transfer member 2 by the positive charge 9 on thebackside 7 of the transfer member 2.

[0045]FIG. 3 demonstrates an example of an embodiment of a belt inaccordance with the present invention. Belt 30 is demonstrated with seam31. Seam 31 is pictured as an example of one embodiment of a puzzle cutseam. The belt is held in position and turned by use of rollers 32. Notethat the mechanical interlocking relationship of the seam 31 is presentin a two-dimensional plane when the belt 30 is on a flat surface,whether it be horizontal or vertical. While the seam is illustrated inFIG. 3 as being perpendicular to the two parallel sides of the belt, itshould be understood that it may be angled or slanted with respect tothe parallel sides. This enables any noise generated in the system to bedistributed more uniformly and the forces placed on each mating elementor node to be reduced.

[0046] The seam formed according to the present invention is one havinga thin and smooth profile, of enhanced strength, improved flexibilityand extended mechanical life. In a preferred embodiment, the belt endsare held together by the geometric relationship between the ends of thebelt material, which are fastened together by a puzzle cut. The puzzlecut seam can be of many different configurations, but is one in whichthe two ends of the seam interlock with one another in a manner of apuzzle. Specifically, the mutually mating elements comprise a firstprojection and a second receptacle geometrically oriented so that thesecond receptacle on the first end receives the first projection on thesecond end and wherein the first projection on the first end is receivedby the second receptacle on the second end. The seam has a kerf, void orcrevice between the mutually mating elements at the two joining ends ofthe belt, and that crevice can be filled with an adhesive according tothe present invention. The opposite surfaces of the puzzle cut patternare bound or joined together to enable the seamed flexible belt toessentially function as an endless belt. In the present invention, theseam including the puzzle cut members, is held together by a polyamideadhesive, which is compatible with the rest of the belt. The belt, inembodiments, provides improved seam quality and smoothness withsubstantially no thickness differential between the seam and theadjacent portions of the belt.

[0047] An example of an embodiment of a puzzle cut seam having two ends,each of the ends comprising puzzle cut members or mutually matingelements is shown in FIG. 4. The puzzle cut pattern may take virtuallyany form, including that of nodes such as identical post or neck 34 andhead 33 or node patterns having projections 36 and receptacles 35 whichinterlock when brought together as illustrated in FIG. 4. The puzzle cutpattern may also be of a more mushroom-like shaped pattern having firstprojections 38 and 39 and second receptacles 40 and 37 as illustrated inFIG. 5, as well as a dovetail pattern as illustrated in FIG. 5 havingfirst projections 41 and second receptacles 42. The puzzle cut patternillustrated in FIG. 7 has a plurality of first fingers 43 withinterlocking teeth 44 and plurality of second fingers 45 which haverecesses 46 to interlock with the teeth 44 when assembled. It ispreferred that the interlocking elements all have curved mating elementsto reduce the stress between the interlocking elements and permit themto separate when traveling around curved members such as the rolls 32 ofFIG. 3. It has been found that with curved mating elements that thestress is lower than with square corners where rather than the stressbeing uniformly distributed it is concentrated leading to possiblefailure.

[0048] Another example of a puzzle cut seam is shown in FIG. 8 in whichthe mutually mating elements or puzzle cut members comprise a firstmember 50 and a second member 51, wherein the first member 50 comprisesa first receptacle 52 and a first projection 54, and the second member51 comprises a second receptacle 55 and a second projection 56. Thefirst receptacle 52 of the first member 50 receives the secondprojection 56 of the second member 51, and the second receptacle 55 ofthe second member 51 receives the first projection 54 of the firstmember 50. In order to reduce the height differential between the seamedportion and the adjacent, unseamed portion of the belt, it is desirableto have the second receptacles formed within their individual members ata substantial depth in a portion of the belt as the belt ends.

[0049] In embodiments, the height differential between the seam and therest of the belt (the nonseamed portions of the belt) is practicallynil, or from about 0 to about 25 micrometers, preferably from about0.0001 to about 25 micrometers, and particularly preferred of from about0.01 to about 5 micrometers.

[0050] A polyamide resin is preferably present between the seam, andplaced in the crevice between the puzzle cut members to a thickness offrom about 0.001 to about 50 micrometers. As shown in one embodiment ofa puzzle cut seam 31 according to the present invention, the adhesive ispresent between the puzzle cut members and at the seam crevice 57 ofFIG. 9

[0051] The adhesive is preferably chosen to have a resistivity withinthe range desired for electrostatic transfer of toner. Preferably, theresistivity of the seam is the same or similar to that of the belt inorder to provide the same electrical properties for the seam and therest of the belt. A preferred volume resistivity for toner transferperformance is from about 10¹ to about 10¹³ ohms-cm, and preferably fromabout 10⁹ to about 10¹³ ohms-cm. When the belt and the seam of the belthave a same or substantially the same electrical resistance, the tonertransfer at the seam is the same or substantially the same as thetransfer at the belt. Such transfer at the seam provides an invisible orsubstantially invisible seam.

[0052] The electrical properties can be tailored by varying the amountof fillers, by changing the type of filler added, and/or by changing thecuring procedure.

[0053] A preferred adhesive for use with a belt seam, preferably apuzzle cut belt seam, is a polyamide resin. In embodiments, thepolyamide resin is alcohol-soluble. By “alcohol-soluble,” Applicantsrefer to materials, which dissolve in alcohols such as butanol, ethanol,methanol and the like. In embodiments, the polyamide resin in theadhesive has functional pendant groups selected from the groupconsisting of methoxy, ethoxy and hydroxy pendant groups. Inembodiments, the pendant functional group is a methoxy methylene group.In embodiments, the polyamide has the following formula:

[0054] wherein n is a number of from about 50 to about 1,000, or fromabout 150 to about 500, or about 270, and wherein R is selected from thegroup consisting of hydrogen; alkyl having from about 1 to about 20carbons, or from about 1 to about 10 carbons, such as methyl, ethyl,propyl and the like; alkoxy having from about 1 to about 20 carbons, orfrom about 1 to about 10 carbons such as methoxy, ethoxy, propoxy andthe like; alkyl alkoxy having from about 1 to about 20 carbons, or fromabout 1 to about 10 carbons such as methyl methoxy, methyl ethoxy, ethylmethoxy, methyl dimethoxy, methyl trimethoxy, and the like; and alkylenealkoxy having from about 1 to about 20 carbons, or from about 1 to about10 carbons such as methylene methoxy, ethylene ethoxy, and the like. Inembodiments, monomers of the above formula can be included in anadhesive composition, wherein R in the monomers can be hydrogen,methylene methoxy, and methylene dimethoxy, or R in the adhesivecomposition can be from about 40 to about 80 mole percent hydrogen, orfrom about 50 to about 65 mole percent hydrogen, or about 64 percenthydrogen; and from about 20 to about 45 mole percent methylene methoxy,or from about 30 to about 35 mole percent methylene methoxy, or about 32mole percent methylene methoxy; and from about 1 to about 10 molepercent methylene dimethoxy, or from about 1 to about 5 mole percentmethylene dimethoxy, or about 4 mole percent methylene dimethoxy.Typical commercially available alcohol-soluble polyamide polymerssuitable for use herein include those sold under the tradenamesLUCKAMIDE® 5003 from Dai Nippon Ink, NYLON® 8, CM4000® and CM8000® bothfrom Toray Industries, Ltd., and other N-methylene methoxy pendantpolyamides such as those prepared according to the method described inSorenson and Campbell, “Preparative Methods of Polymer Chemistry,”second edition, pg. 76, John Wiley & Sons, Inc., 1968, and the like, andmixtures thereof.

[0055] A suitable, fine powder, conductivity-enhancing filler that isuniformly dispersed without large agglomerates in the above resins, canbe used with the present adhesive. In embodiments, the filler is acarbon filler, metal oxide filler, polymer filler, charge transportingmolecule or mixtures thereof. Other conductive fillers include siliconpowder, quaternary salts such as quaternary ammonium salts (for examplesAdogen 464 sold by Aldrich Chemical as methyltrialkyl (C_(8 -C) ₁₀)ammonium chloride), and pyrolyzed polyacrylonitrile particles andfibers.

[0056] In embodiments, the filler is a carbon filler, such as carbonblack, graphite, fluorinated carbon, or mixtures thereof. Preferredfluorinated carbons include those having the formula CF_(x) with xrepresenting the number of fluorine atoms and generally being up toabout 1.5, preferably from about 0.01 to about 1.5, and particularlypreferred from about 0.04 to about 1.4. Other preferred fluorinatedcarbons are poly(dicarbon monofluoride) which is usually written in theshorthand manner (C₂F)_(n). Preferred fluorinated carbons selectedinclude those described in U.S. Pat. No. 4,524,119 to Luly et al., thesubject matter of which is hereby incorporated by reference in itsentirety, and those having the tradename ACCUFLUOR®, (fluorinatedcarbons from Advanced Research Chemicals, Inc., Catoosa, Okla.).Examples include ACCUFLUOR® 2028, ACCUFLUOR® 2065, ACCUFLUOR® 1000, andACCUFLUOR® 2010. ACCUFLUOR® 2028 and ACCUFLUOR® 2010 have 28 and 11percent by weight fluorine, respectively, based on the weight offluorinated carbon. ACCUFLUOR® 1000 and ACCUFLUOR® 2065 have 62 and 65percent by weight fluorine, respectively, based on the weight offluorinated carbon. Also, ACCUFLUOR® 1000 comprises carbon coke, whereasACCUFLUOR® 2065, 2028 and 2010 all comprise conductive carbon black.These fluorinated carbons are of the formula CF_(x) and are formed bythe reaction of C+F₂=CF_(x).

[0057] Preferred metal oxide fillers include titanium dioxide, tin (II)oxide, aluminum oxide, indium-tin oxide, magnesium oxide, copper oxide,iron oxide, and the like, and mixtures thereof.

[0058] Preferred polymer fillers include polypyrrole, polyacrylonitrile(for example, pyrolyzed polyacrylonitrile), polyaniline, polythiophenes,and mixtures thereof.

[0059] Examples of charge transporting molecules include bis(dihydroxydiethylamino-)triphenyl methane (DHTPM), bis(diethylamino)triphenylmethane (TPM), dihydroxy tetraphenyl biphenylene diamine (DHTBD), andthe like, and mixtures thereof. Particularly preferred chargetransporting molecules include DHTPM and DHTBD.

[0060] In embodiments, the filler is present in the adhesive in anamount of from about 1 to about 80, and preferably from about 20 toabout 50percent by weight of total solids. Total solids, as used herein,refers to the amount of polymer resin, filler, crosslinking agent, otheradditives, and other solids present in the adhesive.

[0061] Crosslinking agents can be used in combination with the polyamideto promote crosslinking of the polymer, thereby providing a strong bond.Examples of suitable crosslinking agents include oxalic acid, p-toluenesullfonic acid, phosphoric acid, sulfuric acid, and the like, andmixtures thereof. In embodiments, the crosslinking agent is oxalic acid.

[0062] The adhesive solution may be applied at the seam and betweeninterlocking seaming members, by any suitable means such as using acotton-tipped applicator, liquid dispenser, glue gun and other knownmeans. An amount in slight excess of the amount required to completelyfill the seam kerf when dry of adhesive is added between interlockingseaming members.

[0063] The adhesive may be applied at the seam and between interlockingseaming members by using a solid film tape of the adhesive. The adhesiveis melted into the seam kerf under applied temperature and pressure.Continued heating allows the resin to crosslink.

[0064] In general, the process for seaming using the adhesive hereininvolves compounding the resin with the filler, followed by forming theliquid-phase composite into a solid phase, thin layer, adhesive film.Crosslinking agents such as oxalic acid can be used. The adhesive filmcomposite, with or without a removable release backing, is then appliedto align with only the puzzle-interlocked seamed region of the belt orfilm member. The seam can then be cured by various methods. Curingprocedures useful in curing the seam include room temperature moisturecuring, thermal curing and infrared curing. Examples of heat curinginclude use of moderate heat once the adhesive is placed in the seamcrevice. This moderate heating also increases thecrosslinking/solidification reaction and increases the seam processingand belt fabrication speed.

[0065] The adhesive allows for low-temperature rapid curing, enablingfaster production of belts. In embodiments, the adhesive may be curedbetween the seaming members at a time of from about 1 minute to about 1hour, preferably from about 20 to about 30 minutes, at a temperature offrom about 80 to about 180° C., and preferably from about 100 to about120° C. Heat may be applied by, for example, a heat gun, oven, Vertrodor Sencor seam welder, or other suitable means.

[0066] The substrate is preferably robust enough to undergo multiplecycling through rigorous use. Examples of suitable substrate materialsinclude polyimides with or without conductive fillers, such assemiconductive polyimides such as polyaniline polyimide, carbon filledpolyimides, carbon filled polycarbonate, and the like. Examples ofcommercially available polyimide substrates include KAPTON® and UPLIEX®both from DuPont, and ULTEM® from GE.

[0067] The substrate may include a filler. Preferably, tlhe filler, ifpresent in the substrate, is present in an amount of from about 1 toabout 60, and preferably from about 3 to about 40 percent by weight oftotal solids. Examples of suitable fillers for use in the substrateinclude carbon fillers, metal oxide fillers, doped metal oxide fillers,other metal fillers, other conductive fillers, and the like. Specificexamples of fillers include carbon fillers such as carbon black, siliconparticles, fluorinated carbon black, graphite, low conductive carbon,and the like, and mixtures thereof; metal oxides such as indium tinoxide, zinc oxide, iron oxide, aluminum oxide, copper oxide, lead oxide,and the like, and mixtures thereof; doped metal oxides such asantimony-doped tin oxide, antimony-doped titanium dioxide,aluminum-doped zinc oxide, similar doped metal oxides, and mixturesthereof; and polymer particles such as polytetrafluoroethylene,polypyrrole, polyaniline, doped polyaniline, and the like, and mixturesthereof.

[0068] An example of a preferred belt used in combination with thepolyamide resin adhesive is depicted in FIG. 10. The belt 30 comprises asubstrate 60, having therein, in preferred embodiments, conductivefillers 61. The belt contains seam 31 having an adhesive 63 positionedbetween the seam members 64 and 65. In a preferred embodiment,conductive fillers 62 are dispersed or contained in the adhesive.Conductive fillers 61 optionally dispersed or contained in the substrateand fillers 62 optionally contained or dispersed in the adhesive, may bethe same or different.

[0069] The adhesive herein provides an excellent seam adhesive forbelts, and lo in preferred embodiments, polyimide intermediate transferbelts.

[0070] All the patents and applications referred to herein are herebyspecifically, and totally incorporated herein by reference in theirentirety in the instant specification.

[0071] The following Examples further define and describe embodiments ofthe present invention. Unless otherwise indicated, all parts andpercentages are by weight.

EXAMPLES Example I

[0072] Preparation of Intermediate Transfer Belt

[0073] A polyimide film substrate was obtained from DuPont. The beltsubstrate comprised polyaniline and carbon filled polyimide. Theresistivity was tested and found to be from about 10⁹ to about 10¹⁰ohm-cm. The belt ends that were to be joined were treated with a primershortly before assembly, to help improve adhesion. The puzzle cut endswere wiped with a 10% solution of 3-Aminopropyltriethoxysilane (Aldrich)in toluene and allowed to dry for 10 min at 40° C.

[0074] Optionally, the belt ends to be joined can be subjected to a“chemical etch” treatment to help improve adhesion. The puzzle cut endscan be dipped in 1N aqueous NaOH solution for about 10 minutes, followedby 10 minutes in 1N aqueous HCl solution. The ends can then be rinsedwith distilled water and allowed to dry.

Example 2

[0075] Preparation of Polyamide Adhesive (Sample 1)

[0076] The following were combined in an 8-ounce amber bottle and heatedwith magnetic stirring in a water bath at about 60° C. to make Sample 1:about 4 grams LUCKAMIDE® (from Dai Nippon Ink), about 10 grams methanol,and about 10 grams 1-propanol. A solution formed within 30 minutes. Thissolution was then allowed to cool to about 25° C. Subsequently, about0.3 grams of trioxane (a crosslinker) and about 0.4 grams oxalic acidwere added and the mixture was warmed under about 50° C. tap water untila solution formed. The liquid adhesive was then ready to apply to apuzzle cut seam.

[0077] Alternatively, a “Hot Melt” LUCKAMIDE® adhesive is prepared bysolvent coating a film (3 to 5 mil dry thickness) of the adhesive on arelease substrate, such as corona treated IFS3 Industrial FluorosiliconeRelease Film Number 44461 from Mylan Technologies, Inc., St. Albans,Vt., or TEDLAR® release films from E.I. du Pont de Nemours and Company.The solvent is then allowed to evaporate in an oven at about 50° C.(well under its curing temperature of 110 to 130° C.) for 1 hour. Stripsof the dried semiconductive LUCKAMIDE® adhesive on the release film arecut slightly wider than the puzzle cut seam and are used to weld (underheat and pressure) the puzzle cut seam together.

[0078] To produce a less conductive coating composition, less oxalicacid and/or less DHTBD can be used. To produce a more conductive matrix,the addition of carbon black rendered the composition considerably moreconductive, because carbon black injects charges into the holeconducting matrix under the influence of applied electrical fields.

Example 3

[0079] Preparation of Polyamide Adhesive (Sample 2)

[0080] The formulation described in Example 2 was prepared, except that3.6 grams of DHTBD was used instead of 4 grams, and 0.4 grams of eithertriphenyl methane (TPM) or dihydroxy triphenyl methane (DHTPM) was used.This adhesive was Sample 2.

Example 4

[0081] Preparation of Polyamide Adhesive with Various Amounts of CarbonBlack (Samples 3-8 and Group Samples A-D)

[0082] Samples 3-8 were made as follows. To a 60-mL brown amber bottlewith TEFLON® sealed cap were added: LUCKAMIDE® (4 g), DHTBD (4 g),trioxane (0.3 g, 7.5 wt. %), and various amounts of Black Pearls, 2000carbon black as follows: Sample 3—(0.04), Sample 4—(0.2 g), Sample 5(0.2 g), Sample 6—(0.4 g), Sample 7—(0.6 g), and Sample 8—(0.8 g), and a1 to 1 mixture of methanol and 1-propanol (20 grams) were added. TheLUCKAMIDE®, DHTBD, carbon black and solvent were heated at 160° F. in awater bath to form a dispersion in which all the ingredients except thecarbon black dissolved. Steel shot (60 g) was then added and the cappedcontainer was roll-milled or paint shaken for at least 16 hours. Oxalicacid (a crosslinker) was then added in Group Sample A (0.3 g, or 7.5weight percent based on LUCKAMIDE®), Group Sample B (0.4 g, 10 weightpercent based on LUCKAMIDE®), Group Sample C (0.6 g., 15 weight percentbased on LUCKAMIDE®) and Group Sample D (0.8 g, 20 weight percent basedon LUCKAMIDE®).

Example 5

[0083] Preparation of Polyamide and Carbon Black Adhesive (Samples9-11).

[0084] To a 60-mL brown amber bottle with TEFLON® sealed cap were added:LUCKAMIDE® (4 g), and a 1 to 1 mixture of methanol and 1-propanol (20grams). Black Pearls® 2000 carbon black (0.4 grams in Sample 9, 0.6grams in Sample 10, and 0.8 grams in Sample 11) were then added. TheLUCKAMIDE®, DHTBD, carbon black and solvent were heated at 160° F. in awater bath to form a dispersion in which all the ingredients except thecarbon black dissolved. Steel shot (60 g) was then added and the cappedcontainer was roll milled or paint shaken for at least 16 hours. Oxalicacid (0.3 g, or 7.5 wt. % based on LUCKAMIDE®) was then added.

Example 6

[0085] Preparation of Polyamide Adhesive with Elvamide (Sample 12)

[0086] To a 60-mL brown amber bottle with TEFLON® sealed cap were added:LUCKAMIDE® (1 g), ELVAMIDE® (4 g), DHTBD (5 g), trioxane (0.3 g) and a 1to 1 mixture of methanol and 1-propanol (20 grams). The LUCKAMIDE®,DHTBD, and solvent were heated in a water bath at 160° F. to form asolution in which all the ingredients dissolved. Oxalic acid (0.3 grams,or 7.5 wt. % based on LUCKAMIDE®) was then added. This was Sample 12.

Example 7

[0087] Preparation of Polyamide Adhesive with Elvamide (Sample 13)

[0088] Sample 13 was formed by repeating the procedure set forth inExample 6 except that the following changes in ingredients were made:LUCKAMIDE® (2 grams), and ELVAMIDE® (2 grams).

Example 8

[0089] Preparation of Polyamide Adhesive with PPAN at VariousTemperatures (Samples 14-19)

[0090] To a 60-mL brown amber bottle with TEFLON® sealed cap were added:LUCKAMIDE® (2 grams), pyrolyzed polyacrylonitrile (PPAN) powder (2grams), and a 1 to 1 mixture of methanol and 1-propanol. The LUCKAMIDE®,DHTBD, PPAN and solvent were heated at 160° F. in a water bath to form adispersion in which all the ingredients dissolved except the pyrolyzedpolyacrylonitrile. Steel shot (60 grams) was then added and the cappedcontainer was roll milled or paint shaken for at least 16 hours. Oxalicacid (0.3 grams, or 7.5 wt. % based on LUCKAMIDE® ) and trioxane (0.15grams) were then added. PPAN samples were made by heatingpolyacrylonitrile (Aldrich) at 400° C. for 4 hours (in Sample 14), 350°C. for 4 hours (in Sample 15), 325° C. for 6 hours (in Sample 16), 300°C. for 8 hours (in Sample 17), and 260° C. for 8 hours (in Sample 18).Sample 19 was made as a control for comparison in which LUCKAMIDE® (3grams), solvent (10 grams), trioxane (0.225 grams), and oxalic acid(0.45 grams) were combined in solution.

Example 9

[0091] Preparation of Polyamide Adhesive Tapes with Various Amounts ofPPAN (Samples 20-24)

[0092] Freestanding adhesive tapes were made as follows. To a 60-mLbrown amber bottle with TEFLON® sealed cap were added: LUCKAMIDE® (3grams), particles of polyacrylonitrile pyrolyzed at 300° C. for 8 hours(1.0 g in Sample 20, 1.5 grams in Sample 21, 1 gram in Sample 22, and0.75 grams in Sample 23), trioxane (0.3 grams) and a 1 to 1 mixture ofmethanol and 1-propanol (15 grams). The LUCKAMIDE®, DHTBD, and solventwere heated at 160° F. in a water bath to form a solution in which allthe ingredients dissolved. Steel shot (60 grams) was then added and thecapped container was roll milled or paint shaken for at least 16 hours.Oxalic acid (0.225 grams) was then added. The dispersions were coatedusing a 30 mil gap square applicator onto a corona-treated release paper(Avery, Paper 116626 4N, Buffalo, N.Y.) and air-dried overnight (16hours) at room temperature in a fume hood. The coated dry films wereabout 70 microns thick and were easily peeled from the release paper.The free-standing tapes were stored in a freezer at −21° C. to preservelife. These tapes were compared to another tape (Sample 24) prepared byfollowing the same procedure using ELVAMIDE® (3 grams), PPAN (1 grams),solvent (15 grams), and with no acid and no trioxane.

Example 10

[0093] Preparation of Polyamide and Carbon Black Adhesive Tapes (Samples25-26)

[0094] Freestanding adhesive tapes were made as follows. To a 120-mLbrown amber bottle with TEFLON® sealed cap were added: LUCKAMIDE® (8grams) , Black Pearls® 2000 carbon black (Cabot, 0.4 grams in sample A,0.8 grams in sample B), trioxane (0.6 grams) and a 1 to 1 mixture ofmethanol and 1-propanol (40 grams). The LUCKAMIDE®, DHTBD, and solventwere heated at 160° F. in a water bath to form a solution in which allthe ingredients dissolved. Glass beads (60 grams) were then added andthe capped container was roll milled or paint shaken for at least 16hours. Oxalic acid (0.6 grams) was then added. The dispersions werecoated using a 30 mil gap square applicator onto corona-treated releasepaper (Avery, Paper 116626 4N, Buffalo, N.Y.) and air-dried overnight(16 hours) at room temperature in a fume hood. The coated films wereabout 70 microns thick and were easily peeled from the release paper.The free-standing tapes were stored in a freezer at −21° C. to preservelife. These tapes (Sample 25) were compared to another tape (Sample 26)prepared following the same procedure using ELVAMIDE® (3 grams), PPAN (1grams), solvent (15 grams), and with no acid and no trioxane.

Example 11

[0095] Conductive Polyamide Adhesive Composition with Various Amounts ofAdogen 464 as Release Tape (Samples 27-32)

[0096] LUCKAMIDE® (4 grams), methanol (10 grams) and 1-propanol (10grams) were combined with ADOGEN® 464 (at between 1 and 25 weightpercent based on LUCKAMIDE®) in a 4-ounce amber bottle and heated withmagnetic stirring in a water bath at about 60° C. A solution formedwithin 30 minutes, which was then allowed to cool to 25° C. Trioxane(0.3 grams) and oxalic acid (0.4 grams) were added, and the mixture waswarmed under 50° C. tap water until a solution formed. The adhesive wasready to apply to puzzle-cut seams, or alternatively, a hot meltadhesive tape was made as follows.

[0097] Release paper (Avery, Buffalo, N.Y.) was corona treated, and theadhesive was applied using a 25-mil gap applicator to the corona treatedrelease paper. The coated wet film was then air-dried for at least twohours while the release paper was immobilized under reduced pressure ona platen. The dried adhesive tape was then easily removed from thesubstrate as a free-standing film at about 80 μm in thickness. If notimmediately used, the adhesive tape was then stored in a freezer at −15°C. The adhesive tape was then trimmed to a 4-mm wide strip of about18-inches in length and applied to the puzzle-cut seam of theintermediate belt substrate using a contact welder set at 248° F. underan applied pressure of 90 to 100 psi for 10 minutes. The seamedcylindrical belt was then post-cured in an oven set at 120° C. for 30minutes. The flashing about the welded seam was then removed bypolishing. The resistivity of the tape was measured at 500 volts with aHiresta IP resistivity meter (Mitsubishi Petrochemical Co.). Acylindrical belt made in this way did not show light-dark puzzle-cutseam print out in a Docucolor 12 test fixture under a functional rangeof printer operating conditions in C zone. Bond strength of the seam wasin excess of 19 pounds per linear inch, and the cured adhesive wasresistant to organic solvents such as methanol. Samples had thefollowing amounts of ADOGEN® 464 (weight percent based on LUCKAMIDE®):Sample 27 (0.05 grams, 1 weight percent), Sample 28 (0.1 grams, 2.5weight percent), Sample 29 (0.2 grams, 5 weight percent), Sample 30 (0.3grams, 7.5 weight percent), Sample 31 (0.5 grams, 12.5 weight percent),and Sample 32 (1.0 grams, 25 weight percent).

Example 12

[0098] Preparation of Polyamide Adhesive Film without a Filler (Samples33-36)

[0099] The following were combined in an 8-ounce amber bottle and heatedwith magnetic stirring in a water bath at about 60° C.: LUCKAMIDE® (4grams) obtained (from Dai Nippon Ink), methanol (10 grams), and1-propanol (10 grams). A solution formed within 30 minutes. Thissolution was then allowed to cool to about 25° C. Subsequently, thefollowing components were added to the solution:

[0100] Sample 33: 0.3 grams Trioxane based on weight percent ofLUCKAMIDE®

[0101] Sample 34: 0.3 grams Trioxane and 10 weight percent TPM (0.4grams in 1.6 gram THF)

[0102] Sample 35: 0.3 gram Trioxane and 0.3 gram Oxalic Acid

[0103] Sample 36: 0.3 grams Trioxane, 10 weight percent TPM and 0.3grams Oxalic Acid

[0104] The mixtures were warmed under about 50° C. tap water until asolution formed. The adhesives were coated on Myst-R substrates (DataInstruments 100 Discovery Way, Action, Mass. 01778) at a thickness ofapproximately 16 microns. On top of these films, 0.25 inch goldelectrodes were sputtered for electrical contact. FIG. 11 depicts thevolume, DC conductivities as a function of applied field that wereobtained from standard, unguarded current-voltage measurements.

[0105] The oxalic acid oxidizes DHTBD with the effect of increasing thedensity of free charge carriers; hence, it increases the conductivity.TPM has a tendency to trap or complex, and as a consequence, it isexpected to have the opposite effect. Samples with and without TPM didnot show a significant change in mobility. This result confirms that themechanism is through changes in the charge carrier density rather thanthrough the mobility.

Example 13

[0106] Preparation of Polyamide Adhesive Film with Carbon Black Filler(Samples 37-40)

[0107] To the Sample in Example 12, BLACK PEARLS® 2000 carbon black (1weight percent) was added as charge injection centers. Samples wereprepared and measured as in Example 12. Resulting conductivities areshown in FIG. 12. Samples 37 through 40 in FIG. 12 correspond to Samples33 through 36, respectively, in FIG. 11, except that Samples 37 through40 include the addition of carbon. The whole set of Example 11 isshifted upwards and the departure from ohmic behavior is at earlierfields due to the injecting nature of carbon.

Example 14

[0108] Preparation of Polyamide Adhesive Film with Carbon Black Filler

[0109] The following were combined in an 8-ounce amber bottle and heatedwith magnetic stirring in a water bath at about 60° C.: about 4 gramsLUCKAMIDE® (from Dai Nippon Ink), about 10 grams methanol, and about 10grams 1-propanol. A solution formed within 30 minutes. This solution wasthen allowed to cool to about 25° C. Then, trioxane (7.5 weight percentbased on LUCKAMIDE®), oxalic acid (7.5 weight percent based onLUCKAMIDE:®) were added and BLACK PEARLS® 2000 carbon black was added inamounts of 0.5, 1.0, 2.5 and 5 weight percents.

[0110]FIG. 13 shows conductivities of these samples as a function of thecarbon black loading at different field strengths.

Example 15

[0111] Preparation of Luckamide (Polyamide) and DHTBD Adhesive

[0112] An amount of about 100 grams LUCKAMIDE® was added to a mixture of150 grams methanol and 150 grams 1-propanol in a 1000-ml bottle,. Thebottle was warmed to about 60° C. until the resin completely dissolved.To the warm LUCKAMIDE® solution was added 60 grams DHTBD and thesolution mixed well until all the solid dissolved. To this solution wasthen added 4.2 grams of oxalic acid dissolved in a minimal amount ofmethanol and also 14 grams of BLACK PEARLS® 2000 (carbon black)dispersion. The mixture was placed on a roll mill for 1 hour to ensurecomplete mixing.

[0113] The resulting dispersion was drawcoated onto a sheet of TEDLAR®.A suitable sized coating bar was used. The coating was allowed to dry ina drying oven set at about 40° C. for about 3 hours. Once the film wasdry, it was kept on the release liner and was ready for use as a seamadhesive. The prepared adhesive tape was stored at below 0° C. tomaintain shell life.

[0114] The stock dispersion of carbon black was prepared earlier byattriting 10 grams of BLACK PEARLS® 2000 along with 10 grams LUCKAMIDE®dispersed in 150 grams 1-propanol for about 3 hours, using a bench topattritor charged with {fraction (3/16)}″ stainless steel shot media. Theslurry was filtered through a course screen to separate out the mediaand the carbon dispersion was collected in an 8 ounce polyethylenebottle.

Example 16

[0115] Preparation of LUCKAMIDE® and Fluorinated Carbon Adhesive

[0116] A stock solution of LUCKAMIDE® was first prepared by dissolving50 grams LUCKAMIDE®, 3.5 grams trioxane and 3.5 grams oxalic acid in amixture of 60 grams methanol and 150 grams 1-propanol in a 500 mlbottle. Separately into a 4 ounce glass bottle were added 15 grams ofethyl acetate, 0.15 grams of ACCUFLUOR® 2028 and 0.20 grams ACCUFLUOR®2010 (fluorinated carbons from Advance Research Chemicals, Inc.,Catoosa, Okla.). The carbon blacks were then dispersed in the solvent bymixing and placing the bottle in an ultrasonic bath for about 10 to 15minutes . To the bottle was then added 0.10 grams DIAK3® (Dupont) andthe dispersion was again mixed well. To this bottle was added 27 gramsof the LUCKAMIDE® stock solution and the mixture was placed on a rollmill for about 1 hour.

[0117] The resulting dispersion was drawbar coated onto a sheet ofreleasing film. A suitable sized coating bar was used. The coating wasallowed to dry in a drying oven set at about 40° C. for about 3 hours .Once the film was dry, it was kept on the release paper and was readyfor use as a seam adhesive.

[0118] At this stage, the film did not exhibit any controlledconductivity. In fact, conductivity was only achieved when the film wassubjected to a second thermal post-cure step. A 0.001 inch thick sampleadhesive film coated on stainless steel substrate and post-cured atabout 120° C. for about 30 minutes was observed to have a bulkresistivity of about 10¹⁰ ohm-cm. This formulation was repeated and theelectrical results were found to be reproducible. The resistivity wastuned by adjusting the amount and/or type of fluorinated carbon,curatives, and post-cure parameters.

Example 17

[0119] Preparation of Image-on-Seam Puzzle Cut Seamed Belt

[0120] The two puzzle cut ends of the polyimide film prepared in Example1 were brought together and aligned on the lower jaw of a TechnosealVertrod Thermal Impulse Heat Sealer (Mod. 20EP/P-1/4-WC-CAN-DIG-I) withthe assistance of vacuum holdown tables mounted on both sides of awelder. A freestanding film of the adhesives/release layer (preferablyabout 8 to about 80 microns thick) formed in accordance with any of theexamples above were selected. A narrow strip (about 1 to about 4 cm) ofmaterial was cut to a length and width sufficient to adequately coverthe puzzle-cut seam area on the belt substrate. The strip ofadhesive/release layer was laid across the top of the seam area coveringthe seam. The welder was set to a nominal impulse temperature of about120° C., equivalent to the crosslinking temperature of the LUCKAMIDE®.The seam was welded with applied temperature and pressure for 10 minutesto compression mold the adhesive into the seam kerf, filling itcompletely. This also initiated crosslinking of the adhesive. Postcuring at 120° C. for an additional 30 minutes was required to furthercrosslink and improve the mechanical properties of the adhesive.

[0121] Other methods of hot melt adhesive bonding could be used as well.For example, a heated roll or heated shoe that could move along the seamcan be used.

[0122] The seamed belt was removed from the fixture, post cured, and theseam was subjected to finishing (sanding) and polishing steps to removeexcess adhesive and bring the seam area topography in line with the restof the belt.

[0123] While the invention has been described in detail with referenceto specific and preferred embodiments, it will be appreciated thatvarious modifications and variations will be apparent to the artisan.All such modifications and embodiments as may readily occur to oneskilled in the art are intended to be within the scope of the appendedclaims.

We claim:
 1. An endless seamed flexible belt comprising a first end anda second end, each of the first end and the second end comprising aplurality of mutually mating elements which join in an interlockingrelationship to form a seam, the belt comprising a substrate and theseam comprising an adhesive comprising a polyamide.
 2. An endless seamedflexible belt in accordance with claim 1, wherein said polyamide is analcohol-soluble polyamide.
 3. An endless seamed flexible belt inaccordance with claim 2, wherein said alcohol-soluble polyamidecomprises pendant groups selected from the group consisting of methoxy,ethoxy and hydroxy pendant groups.
 4. An endless seamed flexible belt inaccordance with claim 3, wherein said pendant groups are methylenemethoxy pendant groups.
 5. An endless seamed flexible belt in accordancewith claim 1, wherein said polyamide has the following general formula:

wherein R is selected from the group consisting of hydrogen; alkylhaving from about 1 to about 20 carbons, alkoxy having from about: 1 toabout 20 carbons, alkyl alkoxy having from about 1 to about 20 carbons,and alkylene alkoxy having from about 1 to about 20 carbons, and whereinn is a number of from about 50 to about 1,000.
 6. An endless seamedflexible belt in accordance with claim 5, wherein R is a methylenemethoxy group.
 7. An endless seamed flexible belt in accordance withclaim 1, wherein said adhesive further comprises an electricallyconductive filler.
 8. An endless seamed flexible belt in accordance withclaim 7, wherein said electrically conductive filler is a quaternaryammonium salt.
 9. An endless seamed flexible belt in accordance withclaim 7, wherein said electrically conductive filler is selected fromthe group consisting of carbon fillers, metal oxide fillers, polymerfillers, charge transporting molecules, and mixtures thereof.
 10. Anendless seamed flexible belt in accordance with claim 9, wherein saidelectrically conductive filler is a carbon filler selected from thegroup consisting of carbon black, graphite, fluorinated carbon, andmixtures thereof.
 11. An endless seamed flexible belt in accordance withclaim 9, wherein said electrically conductive filler is a metal oxidefiller selected from the group consisting of titanium dioxide, tinoxide, indium tin oxide, iron oxide, aluminum oxide, and mixturesthereof.
 12. An endless seamed flexible belt in accordance with claim 9,wherein said electrically conductive filler is a polymer filler selectedfrom the group consisting of polypyrrole, polyacrylonitrile,polythiophene, polyaniline and mixtures thereof.
 13. An endless seamedflexible belt in accordance with claim 9, wherein said electricallyconductive filler is a charge transporting molecule selected from thegroup consisting of bis(dihydroxy diethylamino)triphenyl methane,bis(diethylamino)triphenyl methane, dihydroxy tetraphenyl biphenylenediamine, and mixtures thereof.
 14. An endless seamed flexible belt inaccordance with claim 1, wherein said adhesive is crosslinked.
 15. Anendless seamed flexible belt in accordance with claim 14, wherein saidadhesive is crosslinked using oxalic acid as a crosslinking agent. 16.An endless seamed flexible belt in accordance with claim 15, whereinsaid adhesive comprises an electrically conductive filler selected fromthe group consisting of carbon black, graphite, fluorinated carbon,silicon paritcles, and mixtures thereof.
 17. An endless seamed flexiblebelt in accordance with claim 1, wherein said substrate comprises apolymer selected from the group consisting of polyimide andpolycarbonate.
 18. An endless seamed flexible belt in accordance withclaim 17, wherein said polyimide is a polyaniline polyimide.
 19. Anendless seamed flexible belt in accordance with claim 1, wherein saidseam has a volume resistivity of from about 10¹ to about 10¹³ ohms-cm.20. An endless seamed flexible belt in accordance with claim 19, whereinsaid seam has a volume resistivity of from about 10⁹ to about 10¹¹ohm-cm.
 21. An endless seamed flexible belt in accordance with claim 1,wherein said belt is an intermediate transfer belt.
 22. An endlessseamed flexible belt in accordance with claim 1, wherein said pluralityof mutually mating elements are in the form of a puzzle cut pattern. 23.An endless seamed flexible belt in accordance with claim 22, whereinsaid mutually mating elements comprise a first projection and a secondreceptacle geometrically oriented so that said second receptacle on thefirst end receives the first projection on the second end and whereinsaid first projection on said first end is received by said secondreceptacle on the second end to form a joint between the first andsecond ends.
 24. An endless seamed flexible belt in accordance withclaim 23, wherein said first projection and said second receptacle arecurved.
 25. An endless seamed flexible belt comprising a first end and asecond end, each of the first end and the second end comprising aplurality of mutually mating elements which join in an interlockingrelationship to form a seam, said belt comprising a polyimide substrate,and the seam comprising an adhesive comprising an alcohol-solublepolyamide and an electrically conductive filler.
 26. An image formingapparatus for forming images on a recording medium comprising: acharge-retentive surface to receive an electrostatic latent imagethereon; a development component to apply toner to the charge-retentivesurface to develop the electrostatic latent image to form a developedimage on said charge retentive surface; a transfer belt to transfer thedeveloped image from the charge retentive surface to a copy substrate,wherein the transfer belt is an endless seamed flexible belt comprisinga first end and a second end, each of the first end and the second endcomprising a plurality of mutually mating elements which join in aninterlocking relationship to form a seam, the transfer belt comprising asubstrate and the seam comprising an adhesive comprising a polyamide;and a fixing component to fuse the developed image to the copysubstrate.